I have two suggestions, which mirror what some others have said: number one, keep some of your stuff in "his" room. Then you could move some of your least-used stuff to the attic. If he has too much stuff, some of it can go into the attic, too. It's a compromise for both of you.
Number two, make a little sewing or scrapbooking station in another part of the house. I have a great little sewing shed outside, but with two kids I can't use it much, so I keep a sewing machine and basics inside in a little corner of space by the kitchen table, and I sew there most days. I bought a plastic box with a handle at wal-mart that holds my scissors, rotary cutter, pins, etc, and the rotary mat I put flat on the floor under the machine and the box. I also have a tote bag that holds my latest project.